Microsoft has launched legal action against Motorola over alleged patent infringement in the firm's Droid range of Android smartphones.
With just weeks to go before the launch of Windows Phone 7, Microsoft filed suit in federal court as well filing a complaint with the International Trade Commission regarding Motorola's use of the Android smartphone operating system.
Microsoft alleges that Motorola had previously licensed Microsoft technology for smartphones relating to synchronizing email, contacts and calendar but after 2007 continued to use the technology without paying Microsoft.
Nine patents are involved which Microsoft says had surfaced while the company initiated a patent deal with Taiwanese mobile maker HTC earlier this year. HTC is one of the three vendors launching a Windows Phone 7 smartphone while Motorola is absent from the line up.
"The patents at issue relate to a range of functionality embodied in Motorola's Android smartphone devices, including synchronizing email, calendars and contacts, scheduling meetings, and notifying applications of changes in signal strength and battery power," said Microsoft Corporate Veep Horacio Gutierrez.
The action is seen as part of a strategy for casting doubt on the patent exposure of mobile phone manufacturers in choosing to use the Google giveaway Android OS. Microsoft indemnifies manufacturers using Windows Phone 7 against any patent action arising from the use of the new OS.
Motorola said that it would "vigorously defend itself" while Google spokesman Aaron Zamost said: "We are disappointed that Microsoft prefers to compete over old patents rather than new products."